c++ - C/C++ 程序无法在 Raspberry Pi 上正常运行

Question

我编写了程序，通过我的 gmail 地址发送 5 封电子邮件，中间有 1 分钟的暂停时间。该程序适用于我的笔记本电脑，但不适用于 Raspberry Pi。在 Raspberry Pi 上它只发送一封电子邮件。

主要.cpp:

#include <string>
#include <thread>
#include <chrono>

#include "email.c"

void threadFunction()
{
    for (int i = 0; i < 5; i++)
    {
        std::string message = /*"Hello my name is Dmitry\r\nTest1\r\nTest2\r\n" + */std::to_string(i) + "\r\n";
        int status = sent_email("*********", "*********", "Test message", message.c_str(), "smtps://smtp.gmail.com", "*********", "*********");
        std::this_thread::sleep_for(std::chrono::minutes(1));
        status++;
    }
}

int main()
{
     /*std::thread thr(threadFunction);
     thr.join();*/
     threadFunction();
     return 0;
}

电子邮件.c:

#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>

struct upload_information {
    const char *data;
    size_t data_length;
    size_t sent;
};

size_t read_callback(char *buffer, size_t size, size_t nitems, void *instream);

int sent_email(const char *FROM, const char *TO, const char *SUBJECT, const char *message, const char *server, const char *login, const char *password)
{
    CURL *curl;
    CURLcode res = CURLE_OK;
    struct curl_slist *recipients = NULL;

    size_t length = strlen(message) + strlen(FROM) + strlen(TO) + strlen(SUBJECT) + 32; //32 is FROM: <>/n/r, TO: <>/n/r length and SUBJECT + new line(after header - SMTP standart) + /0

    char *data;
    data = (char*)malloc(sizeof(char) * length);

    strcat(data, "FROM: <");
    strcat(data, FROM);
    strcat(data, ">\r\n");
    strcat(data, "TO: <");
    strcat(data, TO);
    strcat(data, ">\r\n");
    strcat(data, "SUBJECT: ");
    strcat(data, SUBJECT);
    strcat(data, "\r\n\r\n");
    strcat(data, message);

    struct upload_information upload_info;
    upload_info.data = data;
    upload_info.data_length = length;
    upload_info.sent = 0;

    curl = curl_easy_init();
    if(curl) {
        curl_easy_setopt(curl, CURLOPT_USERNAME, login);
        curl_easy_setopt(curl, CURLOPT_PASSWORD, password);

        curl_easy_setopt(curl, CURLOPT_URL, server);

        curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
        recipients = curl_slist_append(recipients, TO);
        //recipients = curl_slist_append(recipients, CC);
        curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
        curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);
        curl_easy_setopt(curl, CURLOPT_READDATA, &upload_info);
        curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
        //curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);

        res = curl_easy_perform(curl);

        if(res != CURLE_OK)
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));

        curl_slist_free_all(recipients);
        curl_easy_cleanup(curl);
    }

    free(data);
    return (int)res;
}

size_t read_callback(char *buffer, size_t size, size_t nitems, void *instream)
{
    struct upload_information *upload_info = (struct upload_information *)instream;

    if ((size == 0) || (nitems == 0) || (size * nitems < 1))
        return 0;

    if (upload_info->sent < upload_info->data_length)
    {
        size_t length = size * nitems;

        if (length > upload_info->data_length - upload_info->sent)
            length = upload_info->data_length - upload_info->sent;

        memcpy(buffer, upload_info->data + upload_info->sent, length);

        upload_info->sent += length;

        return length;
    }

    return 0;
}

树莓派上的错误信息:
*** 检测到 glibc *** ./Mailer:双重释放或损坏 (!prev):0x01d0da38 ***

附言树莓派上的程序发送了 1 条正确的消息和第二条消息的一部分。
P.S.S 帖子已更新

Answer 1

您为消息分配的缓冲区不足 1 个字节。您添加的所有常量字符串的总长度为 29，但您还需要为 '\0' 字符添加一个字节，strcat 将终止字符串。

如果运行以下代码，它会显示所有字符串文字的连接长度为 30:

#include <stdio.h>

int
main() {
    printf("%d\n", (int) sizeof("FROM: <" ">\r\n"
                                "TO: <" ">\r\n"
                                "SUBJECT: " "\r\n"));
}

消息还有另外两个问题。一是您没有按要求在 header 和消息之间放置一个空行。另一个是您没有使用 \r\n 终止消息的最后一行。这可能会混淆 curl 库，因为它需要自己添加行尾终止符。否则，邮件将无法通过 SMTP 正确发送。